package com.david.shiro;


import cn.hutool.json.JSONUtil;
import com.david.common.lang.Result;
import com.david.util.JwtUtils;
import io.jsonwebtoken.Claims;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.ExpiredCredentialsException;
import org.apache.shiro.web.filter.authc.AuthenticatingFilter;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMethod;


import javax.annotation.Resource;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @program: Blog-Vue
 * @description:过滤器
 * @author: David
 * @version:
 * @create: 2022-05-09 20:00
 **/
@Component
public class JwtFilter extends AuthenticatingFilter {

    @Resource
    JwtUtils jwtUtils;

    @Override
    protected AuthenticationToken createToken(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        String jwt = request.getHeader("Authorization");
        if(StringUtils.isEmpty(jwt)){
            return null;
        }

        return new JwtToken(jwt);
    }


    @Override
    protected boolean onAccessDenied(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        String jwt = request.getHeader("Authorization");
        if (StringUtils.isEmpty(jwt)) {
            return true;
        } else {
            //校验Jwt
            Claims claim = jwtUtils.getClaimByToken(jwt);
            if (claim == null || jwtUtils.isTokenExpired(claim.getExpiration())) {
                throw new ExpiredCredentialsException("token已失效,请重新登录");
            }
            //执行登录
            return executeLogin(servletRequest, servletResponse);
        }
    }
        @Override
        protected boolean onLoginFailure(AuthenticationToken token, AuthenticationException e, ServletRequest request, ServletResponse response) {

            HttpServletResponse httpServletResponse =(HttpServletResponse) response;
            Throwable throwable = e.getCause() == null ? e : e.getCause();
            Result result = Result.fail(throwable.getMessage());
            String json = JSONUtil.toJsonStr(result);
            try {
                httpServletResponse.getWriter().print(result);
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            return false;
        }

    @Override
    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = WebUtils.toHttp(request);
        HttpServletResponse httpServletResponse = WebUtils.toHttp(response);
        httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
        httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
        httpServletResponse.setHeader("Access-Control-Allow-Headers", httpServletRequest.getHeader("Access-Control-Request-Headers"));
        // 跨域时会首先发送一个OPTIONS请求，这里我们给OPTIONS请求直接返回正常状态
        if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) {
            httpServletResponse.setStatus(org.springframework.http.HttpStatus.OK.value());
            return false;
        }

        return super.preHandle(request, response);
    }
}

